Vanlife Q&A: Those of you who installed roof racks and solar showers, how bad did it hurt your MPG?

In this post in the Van Life Q&A, a user asks:

Those of you who installed roof racks and solar showers, how bad did it hurt your MPG?

My thoughts:

Made very little difference for me. However the wind noise is a factor so plan on addressing that if you can with a deflector.

I have a basket over the cab, a light bar, and a full length rack with solar over the pop top.